(1) Field of the Invention
The present invention pertains to a blower housing that may be used with a climate control furnace or a water heater. The blower housing provides cooling of the motor that rotates the blower fan and provides dilution and cooling of exhaust gases drawn from the furnace or water heater. The housing is constructed of only two pieces and is designed to be easily mounted to a flat surface of the furnace or water heater.
(2) Description of the Related Art
Home or office furnaces and/or water heaters typically include a blower that operates to draw ambient air into the combustion chamber of the furnace or water heater and to expel exhaust gases or fumes from the furnace or water heater through an exhaust pipe or chimney. The typical blower includes a blower housing having a volute shape and a radial fan or a squirrel cage fan mounted in the blower housing. The blower housing has an inlet vent opening at its center communicating with the center of the fan and an outlet exhaust opening at the periphery of the volute shape communicating with the exhaust pipe or chimney. An electric motor is mounted to the blower housing on an opposite side of the housing from the inlet vent opening. The motor rotates the fan to cause the fan to draw exhaust gases and fumes into the center of the fan in the blower housing through the inlet vent opening and exhaust the gases and fumes from the housing through the outlet exhaust opening.
In use of the typical blower with a typical furnace, the inlet vent opening of the housing communicates with an outlet of the furnace heat exchanger. On operation of the blower motor and rotation of the blower fan, a vacuum is created by the fan in the blower housing that draws ambient air into the combustion chamber of the furnace where it mixes with the gas or other fuel combusted in the combustion chamber. The hot combustion gases and fumes produced by the combustion chamber are then drawn through the heat exchanger of the furnace by the blower. The blower fan draws the combustion gases and fumes from the heat exchanger into the blower housing and expels the combustion gases and fumes through the exhaust pipe or chimney communicating with the exhaust outlet of the blower housing.
The typical operation of the blower employed with a water heater is similar to that of the furnace. On operation of the blower, ambient air is drawn into the combustion chamber where it mixes with the gas or other fuel being combusted. The combustion gases and fumes are then drawn through the heat exchanger of the water heater where they heat the water contained in the heater. The combustion gases and fumes are then drawn from the heat exchanger and through the blower housing and are expelled through the exhaust pipe or chimney by the blower.
Improvements in the typical blower used with a furnace or a water heater have included modifications to the blower housing where rotation of the fan not only draws the combustion gases and fumes from the heat exchanger of the furnace or water heater into the housing before being expelled, but the fan also draws a flow of cooling air over the motor rotating the fan to cool the motor. Modifications to the blower housing have also enabled ambient air to be drawn directly into the blower housing to mix with the heated exhaust gases and fumes drawn into the blower housing to dilute and cool the exhaust gases and fumes with the ambient air prior to their being expelled through the exhaust pipe or chimney communicating with the blower housing. However, these modifications to the typical blower housing have complicated the constructions of the blower housing which increases their manufacturing cost. In addition, the modifications to the typical blower housing have also complicated the assembly of the blower housing to the furnace or water heater with which it is used, resulting in increasing the time required to assemble the housing to the furnace or water heater and thereby increasing the assembly cost of the furnace or water heater.
What is needed to overcome these disadvantages of prior art blower housings used with climate control furnaces and water heaters is a blower housing that provides the benefits of motor cooling and exhaust gas dilution and cooling in a simplified, inexpensive blower housing that is easily assembled to the furnace or water heater with which it is used.
The blower housing of the present invention overcomes disadvantages associated with prior art blower housings discussed earlier by providing a blower housing that both draws cooling air over the motor rotating the fan contained in the blower housing and draws cooling and diluting air into the exhaust gases and fumes drawn into the blower housing, where the blower housing has a simplified, inexpensive two-piece construction. In addition, the blower housing provides a compartment for the electrical circuitry that controls operation of the blower motor that encloses all of the circuitry components associated with the motor in the blower housing. Still further, the housing is designed with one side of the housing being positioned in a single plane that facilitates mounting of the one side of the housing on a flat surface of the furnace or water heater with which the blower is used.
The two-piece motor cooling and exhaust diluting blower housing of the invention is constructed with a fan compartment that contains the radial or squirrel cage fan of the blower. The fan compartment has a volute shape with an exhaust inlet opening in one side of the compartment and a shaft hole in an opposite side of the compartment. The peripheral wall of the volute-shaped fan compartment merges into a circular exhaust outlet opening.
The blower housing also has a motor compartment on the side of the fan compartment having the shaft hole. The motor is supported in the motor compartment with the motor shaft passing through the shaft hole to the fan contained in the fan compartment. An inlet vent opening passes through the motor compartment on an opposite side of the motor compartment from the fan compartment. An outlet vent opening exits the motor compartment adjacent its connection to the fan compartment. The inlet vent opening and the outlet vent opening of the motor compartment define a flow path of air that is drawn through the motor compartment on operation of the blower fan that cools the motor contained in the motor compartment.
The blower housing also includes a dilution compartment on the side of the fan compartment through which the exhaust inlet opening passes. The dilution compartment also communicates with the motor compartment through the vent outlet opening of the motor compartment. Thus, rotation of the fan in the fan housing draws exhaust gases through the dilution compartment and also draws cooling air through the motor compartment and mixes that cooling air with the exhaust gases in the dilution compartment before the mixed air and gases are drawn into the fan compartment.
The blower housing also includes a circuitry compartment that contains the electronic circuitry associated with the blower motor. The circuitry compartment is isolated from the fan compartment, the motor compartment and the dilution compartment except for a small opening to the motor compartment that allows the electric wiring of the motor to pass into the circuitry compartment and a small opening to the fan housing that allow a pressure sensor mounted in the fan compartment to communicate with the circuitry in the circuitry compartment.
Because much of the electronic circuitry that controls the operation of the blower motor is mounted on the exterior of the furnace or water heater with which the blower is used, the circuitry compartment is located at the side of the blower housing that is positioned in a single plane. In addition, because the dilution compartment communicates with the exhaust outlet of the furnace or water heater, the dilution compartment is also located at the side of the blower housing that is positioned in the single plane. This enables the blower housing to be mounted to a flat surface of the furnace or water heater with the circuitry compartment enclosing the circuitry components mounted on the flat surface and the dilution compartment enclosing the exhaust outlet of the furnace or water heater emerging from the flat surface.
The arrangements of the fan compartment, the motor compartment, the dilution compartment and the circuitry compartment in the blower housing enable the blower housing to be constructed of only two pieces with each piece being moldable of plastic or another similar material in a two-piece mold. In the two-piece housing construction, portions of the fan compartment, the motor compartment and the dilution compartment are provided on each piece to facilitate assembly of the fan and motor in their respective compartments.